1. Field of the Invention
The present invention relates to a method and apparatus for showing special characters or figures on a rotating disk, and more particularly, to a method and apparatus for showing different characters or asymmetric figures on a rotating disk in accordance with different rotational speed thereof.
2. Description of the Prior Art
In the conventional method and apparatus for showing figures on a rotating disk, a row of radial light fittings (e.g. bulbs, light-emitting diodes, etc.) are disposed on the rotating disk. In addition, a simple circuit is provided for driving the light fittings. When the rotational speed is up to a preset value, the light fittings will be driven to intermittently light up in different cycles. When the rotating disk turns, a plurality of light points produced by different light fittings are distributed on the rotating disk, thereby causing figures by means of the persistence of vision.
However, only a microprocessor of the aforementioned method and apparatus is used to control the lighting duration and cycle of each of the light fittings. Therefore, the figures shown on the rotating disk are simple and symmetric (e.g. spoke-shaped, starlike, polygonal, etc.). When the rotational speed is within the tolerance zone, the shown figures are still all right. However, when it goes beyond the tolerance zone, the expected figures will be deformed. Thus, the conventional method and apparatus disk is applicable in limited situations and shows the figure indistinctly.
It is a primary object according to the present invention to eliminate the aforementioned drawbacks and to provide a method and apparatus for showing special characters or figures on a rotating disk. A sensor is fitted to the rotating disk. The sensor detects the surroundings with inconsistency so that different sensed signals at different points are created when the sensor turns around the central axis once. By deciding the fixing points of the repetitive signals, the rotational cycle of the rotating disk is obtained. After analyzing the rotational cycle, different light fittings on the rotating disk light up at different delay time point. In cooperation with, the persistency of vision of human eyes, the preset complicate figures and characters are therefore shown on the displaying surface of the rotating disk when it rotates.
It is another object according to the present invention to provide a method and apparatus for showing special characters or figures on a rotating disk. A plurality of light fittings (e.g. bulbs, light-emitting diodes, etc.) and a sensor are arranged on the rotating disk. In addition, a circuit is provided for analyzing the surroundings signals detected by the sensor in order to decide the rotational cycle. Meanwhile, the light fittings are driven to intermittently light up at different delay time. When the rotating disk turns, a plurality of light points produced by different light fittings are distributed on the rotating disk, thereby causing figures by means of the persistence of vision of human eyes.
It is a further object according to the present invention to provide a method and apparatus for showing special characters or figures on a rotating disk on which the light fittings are distributed in a nonlinear way on the displaying surface of the rotating disk. In addition, the clearance between the light fittings and the hinge can be different so that a denser scanning route of the light fittings on the displaying surface of the rotating disk is created for a clearer displaying effect.
It is another object according to the present invention to provide a method and apparatus for showing special characters or figures on a rotating disk on which the sensor can be constructed as infrared sensor, spectrum sensor of long and short waves, metal sensor, magnetic field sensor, mechanical contact sensor and sound sensor. Therefore, the present invention has a wider application scope for the convenient design.